August 17, 2005

Diabetes due to antipsychotics?

Researchers Investigate Factors Linked to Development of Secondary Diabetes

Richard Trubo
JAMA. 2005;294,668-670

The American Diabetes Association meeting took place in June and had a symposium focused on secondary diabetes. Secondary diabetes (which is diabetes that starts due to another illness or condition or medication) seems to account for 1% to 5% of all diagnosed cases of diabetes. At the symposium, attention was focused on specific antipsychotic medications and their effect on risk factors for diabetes.

According to John W. Newcomer, MD, associate professor of psychiatry at the Washington University School of Medicine, St Louis, Mo, "Antipsychotic-induced weight gain is associated with an increased risk for insulin resistance". Antipsychotic medications seem to change insulin sensitivity independent of changes in fat.

He talked about a study involving more than 3000 patients with schizophrenia which found that clozapine (Clozaril) may not independently cause diabetes, but instead might increase diabetes risk by producing weight gain or by promoting high blood sugar through an effect on insulin secretion or resistance {This study can be found on PubMed)

Newcome also discussed data stating that while some antipsychotic medications are advertised as "weight neutral," clinical trial results shows that newer drugs like clozapine (Clozaril) and olanzapine (Zyprexa) are associated with a lot of short-term increase in weight; while other medications cause less weight increases. Newcomer said that in large retrospective database analyses of antipsychotics, "about two thirds of the studies have shown that the higher-weight-gain–associated medications seem to have a significant increase in the relative risk or odds ratio for developing diabetes."

Overall, it seems that certain medications (eg. Clozaril and Zyprexa) that are associated with weight gain may cause secondary diabetes.